Door closer



A ril 7, 1959' F. M. NTEWELLI 2,880,450

DOOR CLOSER Filed June 13, 1955 E Mmm T m 2 B noon CLOSER Application June 13, 1955, Serial No. 514,893

-1 Claim. I (Cl. 16-70) This invention relates to door closers, and more particularly to those of the pneumatic check type. v In Altenburger Patent 2,634,454 a door closer is shown in which the plunger rod projects from a hinge member that swings around a stationary vertical shaft. The shaft is encircled by a torsion spring, one end of which is held stationary. The other end of the spring is engaged by the hinge member to resist swinging of the plunger rod and barrel in one direction, whereby the open door will be closed by the spring when the door is released. The plunger that is mounted on one end of the rod is near the outer or front end of the barrel when the door is closed, but there should be a definite space between them in order to assure satisfactory closing and checking. If the closer is installed with the plunger against the front end of the barrel, it is likely that the door will not close completely. On the other hand, if the plunger is too far away from that end of the barrel when the door is completely closed, the full benefit of the checking effect of the air in front of the plunger will not be obtained because the air will not be compressed enough. The door may slam before the checking can take effect. Also, the plunger may strike the rear end of the barrel before the door is opened wide enough. It will therefore be seen that it is important to install such a door closer with just the right amount of space between the plunger and the front end of the barrel.

United States Patent fall off the rod but can easily be removed when desired.

In accordance with this invention the door closer has a barrel with a plunger in it. A plunger rod slidably mounted in the rear end of the barrel is secured to the plunger. The outer end of the rod extends away from the barrel and is provided with a stop near its outer end. Encircling the rod between the stop and barrel is a spacing sleeve of such length that it will limit the distance the barrel can be moved toward the stop during installation of the closer, in order to locate the plunger a predetermined distance from the front end of the barrel. The sleeve is split lengthwise and is deformable to permit it to be removed laterally from the rod after installation has been completed. Preferably, the sleeve is made from paperboard.

The preferred embodiment of the invention is illustrated in the accompanying drawing, in which Fig. 1 is a side view of the door closer, partly in section; and

Fig. 2 is an enlarged vertical section taken on the line IIII of Fig. 1.

This is difficult to do, however, because there is nothing to'keep the barrel from sliding back and forth on the plungerrod while the door closer is being handled and installed. The plunger rod could be provided with a mark to show how far it should project from the barrel, but it has been found in practice that little attention is paid to such marks.

The correct relation of the plunger to the barrel when the door is closed becomes even more important when the side wall of the barrel near its front end is provided with a short inside groove extending lengthwise of the barrel. The purpose of such a groove is to form a bypass back around the plunger for air that is trapped in the front end of the barrel. Slamming of the door is prevented by compression of the air in the front end of the barrel before the plunger reaches the bypass, but just as the door latch reaches the striker plate the plunger passes over the bypass groove so that the compressed air can escape quickly from in front of the plunger. This removes the resistance of the compressed air to the force of the spring, and the door is pulled completely shut by a final jerk. It will be seen that when the door is shut the plunger should be at the front end of the bypass groove and yet spaced from the front end of the barrel. This requires more careful installation of the door closer than is usually practiced.

It is among the objects of this invention to provide a pneumatic check door closer, in which the plunger is readily held the correct distance from the front end of the barrel during installation of the closer, even though the barrel is loosely mounted on the plunger rod, and in which the spacing member that is used for this purpose will not Referring to Fig. 1 of the drawing, the barrel of the door closer is formed from a cylinder 1 having caps 2 and 3 screwed onto its opposite ends. Inside of the cylinder there is a plunger 4, which is mounted on the front or inner end of a rod 5 that extends back through the barrel and out through a central opening in its rear cap 3. The rod extends some distance back beyond the barrel and has its outer end screwed into a U-shape hinge member 6 that is oscillatable around a square vertical shaft 7 mounted on a bracket 8 that is connected to the side of a door frame 9 by screws 10. Inside of the hinge member the shaft is encircled by a bushing 11, around which a torsion spring 12 is coiled. The opposite ends of this spring are turned outward and project through slots 13 in the side of the hinge member. The spring resists turning of the hinge member in one direction around the square shaft and therefore tends to return the hinge member to its original position Whenever it is turned away from that position. For a more complete description of the construction and operation of this biasing mechanism ofthe door closer, reference is made to the Altenburger patent mentioned hereinbefore.

The front cap 2 of the barrel is provided with the usual adjustable valve screw 16 that controls the escape of air from the barrel in front of the plunger as the front cap and plunger move toward each other. Also projecting from the front cap is an integral lug 17 that extends into the fork of a small bracket 18 that is adapted to be connected to the door 19 by screws (not shown) extending through holes 20 in the bracket. The lug and bracket are pivotally connected together by a pin 21 extending vertically through them and held in place by a cotter key 22.

When such a door closer is in use, attached to both door and frame, the torsion spring 12 will be coiled more tightly around bushing 11 as the door is swung open, because the swinging plunger rod will turn hinge member 6 around the square shaft. Also, the barrel will be pulled forward on the plunger and rod. When the door is released, the spring will swing it closed but the closing speed is determined by the rate at which air can escape from the front end of the barrel through the valve. While the door is shut, the plunger should be far enough from the front end of the barrel to insure that the closer will not interfere with closing of the door. On the other hand, the plunger should be close enough to the front end of the barrel to have provided between them a cushion of compressed air in time to have kept the door from slammmg.

In order to give the door a quick pull at the very end of its closing movement so that the latch will slide over the usual striker plate and snap into place, a short longitudinal groove 25 may be formed in the inside of the barrel near its front end. This groove should be just long enough to permit air from in front of the plunger to pass back around the plunger into the space behind it as the plunger moves forward over the groove. By the time the plunger has reached the front end of the groove, the door should be completely closed. The bypass groove can be formed by pressing a section of the cylinder wall outward.

While this door closer is being handled and installed it will be seen that there is nothing to prevent the barrel from moving back and forth on the plunger. Yet, for the reasons just given, the bracket 18 at the front end of the barrel should be connected to the door in such a location that the plunger will be in a predetermined location inside the front part of the barrel. Therefore, to make it easy for the Workman to correctly position the barrel on the plunger rod while bracket 18 is being screwed to the door, a spacing sleeve 30 is loosely mounted on the projecting portion of the plunger rod by the manufacturer of the closer. This sleeve is located between the usual hold-open washer 31 and the rear end of the barrel. When a flat washer is used, as shown in the drawing, it is canted on the rod when in hold-open position by means of a projection 32 on the rear cap 3. The spacing sleeve is of such length that when the barrel is moved back against it and the washer is thereby pushed back against hinge member 6, as shown in Fig. 1, the barrel will be located the correct distance from the hinge member. The correct distance is the one that positions the plunger the proper distance from the front end of the barrel; that is, at the front end of the bypass groove 25. The sleeve practically or completely encircles the rod so that it will not fall off the rod when not engaged by the hold-open washer and barrel. The sleeve must be deformable and slit lengthwise at 33 most or all of the way through, to permit it to be spread open and removed laterally from the rod after the closer has been installed. Preferably, the sleeve is made from an inexpensive material, such as paperboard. The sleeve can be opened up to remove it by merely slipping the fingernail or a screwdriver into its slit and then spreading the edges apart.

In installing this door closer the large bracket 8 is mounted on the door frame first and then the biasing mechanism is connected to the bracket by a screw 35. When the other bracket 18 is swung back against the door, the

4 7 holes 20 in it will be in correct position for attachment of the bracket to the door if the workman holds the barrel against spacing sleeve 30, as shown in Fig. 1. After the door closer has been installed in this manner, the spacing sleeve is opened and pulled sideways off the plunger rod. It has no further use and can be discarded.

According to the provisions of the patent statutes, I have explained the principle of my invention and have illustrated and described what I now consider to represent its best embodiment. However, I desire to have it understood that, within the scope of the appended claim, the invention may be practiced otherwise than as specifically illustrated and described.

I claim:

The combination with a door closer having a barrel adapted to be connected at its front end to a door, a plunger loosely mounted in the barrel, a plunger rod slidably mounted-in the rear end of the barrel and secured to the plunger, the rod extending rearwardly away from the barrel, a hinge bracket having a hub projecting toward the barrel and screwed on the outer end of said rod, the bracket being adapted to be mounted on a door frame whereon the door is hinged, and a torsion spring associated with the hinge bracket for resisting swinging of the bracket after the closer has been installed on said door and frame, of a stop washer of larger diameter than said hub slidably mounted on the plunger rod adjacent the hub, and a paperboard spacing sleeve of smaller diameter than said washer slidably mounted on the rod between the washer and barrel, the inner surface of the barrel near its front end being provided with a longitudinally extending by-pass groove of slightly greater length than the plunger, the sleeve being of such length that when engaged by both the stop washer and barrel while the washer is against said hub during installation of the closer said by-pass groove will be located directly behind the plunger, and the sleeve being split lengthwise and deformable to permit it to be opened far enough to be removed laterally from the rod after said installation.

References Cited in the file of this patent UNITED STATES PATENTS 408,336 Breed Aug. 6, 1889 1,916,571 Hoflman July 4, 1933 2,634,454 Altenburger Apr. 14, 1953 2,703,907 Newell Mar. 15, 1955 

